Field of the Invention and Description of the Prior Art
The present invention relates to a method for making overhead projection transparencies.
Prior art overhead projection transparencies are normally made in the form of a transparent photocopy from a master which is placed on the glass plate of a photocopying machine. Before feeding the transparency through the photocopying machine, the transparency is either provided with strips of non-glossy material in order to suit the gripping mechanisms of the photocopying machine or attached to a paper backing serving as a support for the transparency and providing engagement with the feeding mechanism of the photocopying machine. Unless the photocopying machine is of the expensive multi-color type, such transparencies normally provide the information on the transparency in one color only, conventionally black. This one color representation on the transparency requires in several cases further treatment of the transparencies with colors from specially made pens in order to color diagrams etc. This is quite often a tedious and complicated task requiring utmost care in order to obtain a satisfactory result. One major disadvantage when applying color onto the transparency, is that the transparency has a very glossy surface, occasionally with an oily like coating.